Fluid heater



V. W." MORAY April 18, 1939.

FLUID HEATER 2 Sheets-Sheet 1 Filed Feb. 3, 1937 BNVENTOR M/fi/L M/MO/PAY ATTONEY April 18, 1939. v w MORAY 2,154,764

I FLUID HEATER Filed Feb. 5, 1937 2 Sheets-Sheet 2 ATTORNEY PatentedApr. 18, 1939 UNITED STATES FLUID HEATER Virgil W. Moray, Bronx, N. Y.,assignor to Akwa Heaters, Inc., New York, N. Y., a corporation of NewYork Annllcation'rebrue 3, 1937, Serial No. 123,794

5 Claims.

This application is a reflle of my earlier application Serial No.29,814, filed July 5, 1935.

The invention relates to fluid heaters and more particularly pertains tosteam boilers and water 5 heaters and to auxiliary means for heatingwater or other fluids.

The invention provides a novel arrangement of auxiliary fluid heatingcoils in steam boilers and the like, which provides certain advantagesover 10 arrangements heretofore in use. One of the important advantagesis that the presence of the auxiliary coil in the steam boiler increasesthe boiler emciency for the reason that the coil enhances the normalcirculation of water in the boiler both in point of velocity and volume.Other advantages are: A relatively long heating coil may be installedfrom the side of the boiler; the heating load on the boiler isdistributed over a large area within the boiler, thereby increasing theefliciency of the boiler; the coil may be installed from the side of aboiler notwithstanding the presence of walls or other obstructionsdisposed closely adjacent one or more sides of the boiler; acomparatively small sleeve adapter for.

25 the coil will be sufllcient -which will reduce the cost of the coil;the sleeve adapter may be so shaped and attached to the boiler shellthat rapid circulation of boiler water is obtained, thereby materiallycontributing to the heating emciency;

0 the auxiliary coil may be readily removed for repair or other purposemerely by detaching the coil head from the sleeve adapter, and since thecoil is installed from the side of the boiler, no protecting means arenecessary to prevent cor- 35 rosion of the coil head.

The invention will be understood from the following descriptionconsidered in connection with the accompanying drawings forming a partthereof, which illustrate a preferred arrangement of a boiler andauxiliary fluid heating coil, and in which:

Fig. 1 is a perspective view with parts of the boiler shell broken away,of a fire tube boiler having a submerged fluid heating coil arranged anddisposed in accordance with the present in'- vention;

Fig. 2 is a plan view of the boiler shownin Fig. 1 with parts of theshell broken away;

Fig. 3 is a front end view of the boiler with part of the shell brokenaway;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 2, and

Fig. /5 is a sectional view taken on line 55 of Fig. 2.

Like characters of reference refer to the same parts throughout theseveral views.

Referring to the drawings, reference character Ill designates the shellof a fire tube boiler having fire tubes ll extending longitudinallythere- 5 of between spaced tube sheets I2 and I3. The front end of theboiler is provided with a fire box l4 having side walls l5 and I6 whichare connected at their upper ends by a crown sheet H. The side walls l5and it are spaced from 10 the shell III to provide water legs l8 and Hwhich communicate at their upper ends with the steam and water space 20.The volume of water in the boiler is maintained substantially at thelevel L (Fig. 3) or at any other-level which is sufflciently high tocover the tubes of the auxiliary heating coil to be described. A steamreturn line 21 is connected into the bottom of the rear water leg of theboiler.

In the arrangement shown, the tubes of the auxiliary heating coil arearranged obliquely at an angle of substantially 45 to the direction ofextent of the boiler tubes. It will be understood however, that thetubes of the coil may be disposed at other oblique relationships, or atany 25 desired acute angle to the boiler tubes between substantiallyright angular and substantially parallel positions.

The auxiliary fluid heating coil shown comprises a plurality of looptubes 22, the ends of which are secured to a coil head 23 which isdetachably secured to the flanged outer end of a coil sleeve adapter 24,the inner end of which is welded to the boiler shell l0 In thisinstance, the sleeve 24 is of substantially rectangular configuration intransverse cross-section with armate walls as shown in Fig. 5, but maybe of other configurations, such as circular, if desired. The coil tubes22 are inserted through the sleeve adapter 24 and the head 23 is boltedto the sleeve by a plurality of nuts and bolts 25. The sleeve adapterneed only be long enough to permit the ready securement of the coil headto the sleeve, but it may be of any convenient or desired length.

Fluid to be heated is supplied to the coil through a pipe 26 and theheated fluid is withdrawn through pipe 21. The coil may be arranged fora single pass of the fluid through the tubes thereof as shown, or it maybe arranged for-a plurality of passes. The coil tubes are made as longas is practically possible to provide the greatest possible area ofheating surface for the coil within the boiler. The tubes of theauxiliary coil may rest upon the boiler tubes II or suitable means maybe employed for supporting the coil out of contact with the boilertubes.

With the auxiliary heating coil arranged and disposed as illustrated inthe drawings, the normal circulation of the water in the boiler isincreased in point of velocity and volume and additional boiler watercirculation is set up. This is due to the fact, as shown by the arrowson the drawings indicating the direction of flow of the water duringoperation of the boiler, that the auxiliary heating coil surface is sodisposed that the hot water in the boiler upon coming in contact withthe tubes of the coil and giving up part of boiler water in the rearportion of the boiler isin a direction toward the water legs andtherebyincreases the rate at which the water rises in the water legs. Morespecifically the auxiliary coil is not disposed directly above the crownsheet l1, so that there will be no fall of relatively cold water fromthe tubes of the coil onto the crown sheet. Since heat is transferredfrom the combustion gases through the crown sheet at a high rate, thenormal circulation of water inthe boiler will be upwardly and toward therear of the boiler from the crown sheet. Should any substantial part ofthe auxiliary coil surface be disposed above this crown sheet, it willbe apparent that counter-currents will be set up with respect to thenormal boiler circulation which will adversely affect to a nfigarialextent the efilciency of the boiler. With the coil disposed as shown inthe drawings, that part of the coil within the boiler which is in thevicinity of the crown sheet is disposed over the water leg i9 so thatthe boiler water which is cooled by contact with the coil will flowdownwardly along the outside of the water leg, asindicated in Fig. 3,along with the water from the rear part of the boiler which flows towardthe water legs. It will be observed, that the cool water in water leg l9flows downwardly in contact with the outer shell l0 and the hot waterflows upwardly in both water legs l8 and I9 along the inner portionsthereof adjacent the side wall I6, so that cool water does not come incontact with the heated surfaces surrounding the fire box.

With the coil arrangement disclosed, it will be perceived that arelatively long coil may be installed in a boiler through the side ofthe boiler shell. Also, as will readily be seen from an inspection ofFig. 5, the area of the opening 30 between the coil sleeve 24 and theboiler I0 is comparatively large thus permitting rapid circulation ofthe boiler water through thecoil sleeve and high efflciency of heatingof the fluid in the coil. It will also be perceived that since the tubesof the heating coil extend through a large area of the boiler, theheating load on the boiler will be distributed with the result thatgreater boiler efllciency is obtained. Moreover, the heating coil mayreadily be installed in the boiler and removed therefrom when the boileris flanked by walls disposed closely adjacent thereto. To remove thecoil, it is only necessary to unbolt the head from the coil shell andthe entire unit may be removed.

Although an auxiliary heating coil having an example of this arangement,the tubes of the coil may extend from the coil' head obliquely to theboiler tubes adjacent the head and then may be curved so that the endsof the tubes remote from the coil head are parallel or substantiallyparallel to the boiler tubes.

By the expressions oblique or obliquely as used herein and in theclaims, is meant the disposition of the coil tubes, or the portionsthereof adjacent the head end, with respect to the boiler tubes so thatthe coil tubes are positioned at an angle to the boiler tubes between asubstantially right angular position and a parallel position regardlessof the particular direction in which the tubes of the coil extend. Theseexpressions are also intended to include auxiliary fluid heating coilshaving curved tubes or curved portions of tubes as hereinbeforementioned, wherein the tubes areinstalled through the side of the boilershell obliquely to the boiler tubes.

In some instances, it may be desirable to arrange the coil so that partof the coil is above a part of the crown sheet of the fire box. One sucharrangement would result from installing the coil so that it passedthrough the boiler shell at a point more forward of the boiler thanillustrated in Fig. 2, in order that the coil would pass over a cornerof the crown sheet. This arrangement would operate satisfactorily, butthe boiler efllciency would not be quite as great, due to the .fall ofcool water from the coil onto the crown sheet. However, such anarrangement when the greater part of the area above the crown sheet isfree of coil tubes, is within the scope of the shell, fire tubes in theshell at least some of which extend substantially horizontally from oneend of the fire box, and an auxiliary fluid heating coil havingsubstantially horizontally extending tubes in the shell arrangedobliquely to the fire tubes and disposed substantially entirely in thezone of the horizontally extending fire tubes.

2. A boiler comprising a shell, a fire box in the shell, fire tubes inthe shell at least some of which extend substantially horizontally fromthe fire box, and an auxiliary fluid heating coil having substantiallyhorizontally extending tubes in the shell arranged obliquely to the firetubes and dis posed above the fire tubes and substantially entirelywithin the zone of the horizontally extending fire tubes.

3. A boiler comprising a shell, a fire box in the shell, fire tubes inthe shell at least some of which extend substantially horizontally fromone end of the fire box, and an auxiliary fiuid heating coil havingsubstantially horizontally extending tubes which extend through a sidewall of the shell with portions thereof within the shell arrangedobliquely to the fire tubes and disposed substantially entirely withinthe zone of the horizontally extending fire tubes.

4. A boiler comprising a shell, a fire box .in the shell, fire tubes inthe shell at least some of which extend substantially horizontally fromone end of the fire box, and an auxiliary fluid heating coil havingsubstantially horizontally extending tubes in the shell submerged in thewater therein and arranged obliquely to the fire tubes and disposedsubstantially entirely in the zone of the horizontally extending firetubes.

5. A boiler comprising a shell, 2, fire box in the shell, fire tubes inthe shell at least some of which extend substantially horizontally fromone end of the fire box, the shell having an opening in the side thereofabove the fire tubes, a sleeve adapter secured to the shell so as tocover the opening and having its longitudinal axis disposed obliquely tothe longitudinal axis of the boiler, and a fluid heating coil extendingthrough the sleeve adapter into the shell and above the fire tubes andconnecting with a coil head secured to the adapter, the tubes of thecoil extending substantially horizontally and being disposed obliquelyto the horizontally extending fire tubes.

VIRGIL W. MORAY;

